This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The need for more studies in natural environmental settings is required to truly understand the mechanisms behind expression patterns of a population and to determine if this is due to the inheritance of specific adaptive traits. The inconsistency of results between laboratory experiments and field studies illustrates the need for interdisciplinary studies in natural environments. We established a common garden of inbred lines and maternal families of Boechera stricta within and just outside a naturally occurring patch to evaluate the role of known stress response pathways and candidate traits (defensive compounds and water use efficiency) in determining niche boundaries and to estimate their evolutionary potential. B. stricta is another close wild relative of Arabidopsis, enabling the use of genomic tools such as microarrays for genomewide transcript profiling (see below under Methods). Thus we are combining the tools of quantitative genetics, physiological ecology, chemical ecology and genomics in this field experiment to understand issues of the niche that are fundamentally important to evolutionary ecologists. Dr. Siemens hosted a fellow from USF during the summer of 2010.